empty class

Reference: http://www.spongeliu.com/260.htmlWhy is C + + hollow class and empty struct size 1?On November +, in C language, language learning, by spongeThis article is a translation, with the previous article echoed, the original text here.For

The well-known C + + Hollow class has a size of 1, but there are quite a few developers who have a lot of ambiguity about the size of a class that has no member variables other than the empty class. Here we take the following code as an example:

Recently in the review of some basic C + +, feel this article is very good, reproduced, we look!The size of the memory that the class occupies is determined by the member variable (except for the static variable ), and the member function ( which is

The x64 environment is implemented:1#include 2 3 using namespacestd;4 5 classkong{6 7 };8 9 classkong1{Ten One }; A - classkong2{ - the }; - - classdata2 - { + intA//4 bytes - Chars; + }; A at classdata3 - { - intA; - Chars; -

The significance of private inheritance lies in "be implemented in turns ".Private inheritance and public inheritance are completely different, mainly reflected in two placesFirst, the public inherits the permission of the parent class in the

This article mainly discusses the memory layout of C ++ pairs. How is a simple or complex C ++ class stored in memory? Each class has data members and interfaces. Are they stored in the same way? Why does a virtual function incur storage overhead?

Preface This article tracks the assembly code of function calls by observing the memory layout of objects. Analyzes the layout of the C ++ object memory, the execution methods of virtual functions, and virtual inheritance.I wrote this article

1: first look at the size of an empty class: #include using namespace std;class A{}; int main(int argc, char** argv) {cout The result of sizeof (a) is 1; #include using namespace std;class A{public:A();~A();}; int main(int argc, char** argv)

I have previously written the number of bytes for viewing the C ++ data type, but in practice, we are more concerned with the size of struct and class. First, let's look at the size of the empty class, as shown below: class VoidClass{}; Run the

C + + Various types of sizeof size, first put test code and test results (VS2013).#include using namespace STD;//////////Test base type//////////intGetarraysize (CharStr[]) {return sizeof(str);}voidTestsizeofbase () {cout"//////////test base type////

*************************************** Reprint Please specify the Source: Http://blog.csdn.net/lttree ********************************************Ii. Constructors,destructors and Assignment Operatorsfrom the first chapter to understand C + +, began

Question: What is sizeof for an empty class? Let's take a look at the test code. The result is printed on the G ++ 4.5 64bit machine. #include using namespace std;class ClassA {};class ClassB { private: int b;};class ClassC : public ClassA

There are two basic methods for class inheritance Basic Principle of object impersonating: constructor uses the this keyword to assign values to all attributes and methods (constructor is actually only a value assignment function). Therefore, you

Postscript Based on the previous discussion, we can see that as long as virtual inheritance is involved, the code generated when accessing the member variables of the parent class is quite inefficient, the address of the member variable needs to be

1:An empty class is no longer empty after the C + + compiler is processed, and the compiler automatically declares some member function for us if you writeClass a{};After the compiler is processed, it is equivalent to:Class A{PublicA (); Default

What is the size of the class? To be exact, a class is just a type definition, and it is no size. Using the sizeof operator for a type name operation, you get the size of the entity with that type. First of all: we want to know what is the

The following blog reproduced from others, I was also the problem of the pit for almost two days, about a variety of virtual base classes, virtual inheritance, virtual functions and data members, such as a series of memory-alignment issues again

Http://www.cnblogs.com/fanzhidongyzby/archive/2013/01/12/2858040.htmlC + + objects can be created in two ways: constructors and copy constructors. Suppose we define class aand use it to create an object.A A, B;A C=a;A d (b);Objects a and b are

C + + objects can be created in two ways: constructors and copy constructors. Suppose we define class A and use it to create an object. Copy Code code as follows: A a,b; A C=a; A d (b); Objects A and B are created using the

C + + class occupies memory size calculationDescription: The author's operating system is 32-bit.Class A {};sizeof (A) =?sizeof (A) = 1Obviously is empty class, why does the compiler say it is 1?Empty classes can also be instantiated, each instance